[ Official ] How was the Prelims 2021 paper?

https://cpcb.nic.in/displaypdf.php?id=SW5kdXN0cnktU3BlY2lmaWMtU3RhbmRhcmRzL0VmZmx1ZW50LzQyNC5wZGY= 

www.cpcbenvis.nic.in/scanned reports/PCL 4 Environmental Stahttp://www.cpcbenvis.nic.in/scanned%20reports/PCL%204%20Environmental%20Standards.pdfndards.pdf

CPCB norms for copper smelting industry

If there was concern of emission of CO in the environment in lethal quantity, CPCB must have added.